Circuit Description
The interior lamp dimmer is a potentiometer. It is powered by the climate control panel (CCP). The CCP determines the level of dimming desired based on the voltage from the interior lamp dimmer. The CCP converts the interior lamp dimmer feedback voltage to a digital signal and sends out a class 2 message to the dash integration module (DIM).
Conditions for Running the DTC
| • | The CCP must be powered. |
| • | DTC B1327 must not be present. |
Conditions for Setting the DTC
The feedback voltage is greater than 4.8V for more than 900 milliseconds.
Action Taken When the DTC Sets
The CCP sets the dimming level to full brightness for all displays.
Conditions for Clearing the DTC
The CCP does not detect a voltage that is greater than the predetermined value during the diagnostic self test.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Lighting System Diagnostic System Check? | -- | ||
2 |
Does the scan tool indicate the volts are within the specified range? | 0.2-4.8 V | ||
Does the voltage measure near the specified value? | 5 V | |||
4 | Measure the voltage from the 5 volt reference circuit to the sensor return circuit at the fog lamp switch connector. Does the voltage measure near the specified value? | 5 V | ||
5 | Measure the voltage from the interior dim pot signal circuit to the sensor return circuit at the fog lamp switch connector. Does the voltage measure near the specified value? | 0 V | ||
6 |
Does the scan tool indicate the volts are near the specified value? | 5 V | ||
7 | Test the 5 volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 | Test the sensor return circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
9 | Test the interior dim pot signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
10 | Inspect for poor connections at the fog lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
11 | Inspect for poor connections at the CCP module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
12 | Replace the fog lamp switch. Refer to Fog Lamp Switch Replacement . Did you complete the replacement? | -- | -- | |
13 | Replace the CCP module. Refer to Control Assembly Replacement in HVAC Systems - Manual. Did you complete the replacement? | -- | -- | |
14 | Operate the system in order to verify the repair. Did you find and correct the condition? | -- | System OK |
